Improvement in pneumatic railways



T. W. RAMMELL. PNEUMATIG RAILWAY.

No. 42,509. Patented Apr. 26, 1864.

F CEt THOMAS WEBSTER RAMMELL, OF LONDON, ENGLAND.

IMPROVEMENT IN PNEUMATIC PiAILWAYS.

Specification forming part of Letters Patent No. dfifl flw, dated April 26, 1864.

To azz whom it may concern:

Be it known that I, THOMAS WEBSTER RAM- MELL, of London, in the county of Middlescx, civil engineer, a subject of the Queen of Great Britain, have invented or discovered new and useful Improvements in Pneumatic Railways and Tubes and I, the said THOMAS WEBSTER ItArmnnLL, do hereby declare the nature of the said invention, and in-what manner the same is to be performed, to be particularly described and ascertained in and by the follow. ing statement thereofthat is to say:

Thisinv'ention consists of improved railways and tubes for the carriage or conveyance of passengers, goods, parcels, or letters by means of atmospheric agency, and of im proved means of propelling and regulating the trniiic upon or through such railways or tubes. The rails, grooves, or trams constituting the way arein all cases placed within tunnels or tubes, and the traflic is carriedwithin and through the tunnels or tubes. The carriages upon or in which the traflic is placed rest and move immediately upon and are directed. in their motion by these rails, grooves, or trams.

The railways are peculiarly adapted for underground communication in large towns; but they may be placed upon the surface orupon a raised structure, and may be used either for town or for country lines.

I now proceed to describe the construction and mode of working of a railway for the conveyance of passengers and goods accord ing to my invention.

- I construct a hollow way or tunnel of brickwork, iron, or other suitable material, .within which the train of carriages is to travel, having' terminal stations and snchintermediate stations (if any) as-may be required.

Figure 1' shows a transverse section of a tunnel as constructed of brick-work for an underground railway. Fig. 2 shows a transverse section, and Fig. 3 a longitudinal elevation, of atunnel or tube of iron or other metallic ma. terial upona raised structure, as adapted for railways above ground,especial ly in towns.

I prefer to make the casing or internal we face ofthe tunnel of the usual tunnel form, as

shown in those figures, but other shapes would answer. Upon the invert I place the framework and rails constituting the permanent way, preferring a rail and sleeper with a continuous bearing and filling in the frame-work solidly, and in such manner that it may present a perfectly even upper surface.

The carriages I employare mounted in much the same manner as thoseiu ordinary use upon railways, and I prefer to have them of the same form in transverse section as the interior of the tunnel, as shown at B B BB in Fig. l, and a few inches less in each direction, and in order that the same clear space may be pro-- served all round I frame out the carriage (see B B)'in one or more places underneath, so that it may in like manner clear the bottom and lower sides of the tunnel by an equal space. I fill in the vacantspace so left between the carriage and the tunnel. with a soft or yielding material, which is fixed to and moves along with one ormore of the carriages, and which in the passage through the tunnel yields to any inequality in the interior surface. The soft material I prefer to use for filling up the intermediate space left is some kind of matting made witir'a pile, and I apply it in strips of, say, a foot to fifteen inches wide, one or more to each carriage; but any other soft material which will prevent undue leakage of air may be used..

It is to be observed that the carriages need not necessarily be f the same shape as the tunneLbutthat any form of carriage may be used, provided it be'.framed out in the manner'described, so as to fit'the tunneh'ofvwhate ever shape that may be, and also that only one carriage of a train, which. may be called the piston' carriage, need be made to fit the tullnel.

The soft material interposed is intended to prevent excessive leakage of air in the application of the power; but if the carriage fits closely, or nearly so, to the tunnel, and the leakage is inconsiderable, it may be dispensed with.

For propelling and working the train of carriage Imake use of atmospheric agency, the pneumatic pressure being applied over the whole tranverse area of the carriage by rarefyins and expelling the air in front of the train. For this purpose I use a pump worked by steam-power, or water or other power, and I much prefer one upon the rotary principle, in which the air is expelled or pumped out by the action of the centrifugal force; but any other form of air-pump may be used.

The arrangements I propose for the practical application of the power, and the working and regulating of the traffic, are as follows:

Fig. 4 shows a plan of a portion of a single line of railway, A A A, with a terminal sta tion, B B, and an intermediate station, 0 C.

Fig. 5 shows a portion of the line ofrailway, and the intermediate station, 0 (J, on a la ger scale.- The line is nrade'double at the intermediate station, to allow the up and down trains to pass, the part D D being reserved for down trains, and the part E E for up trains. At the terminal and each intermediate station, or where necessary,'I erect a steam-engine or other machine of the requisite power, and in connection with it proper pumping machinery, as above explained, working in a suitable exhaustchamber, F F, into which is conducted the end of a shaft or air-passage, G G G G, proceeding from the tunnel at a point, Z Z, placed at some little distance-say from'fit'ty to one hundred yards-from the station. I place in the air-passage a valve, H'H, communicating between the tunnel and the exhaust-chamber, and also another valve, L L, communicating between the tunnel and the outer atmosphere, and both of which are made to open and to close, either by hand or automatically, as may be most convenient. I also place across the tunnel, at every terminal and intermediate station, valve-doors K K K,

covering the entire area of the tunnel and opening outward into the station. I connect the stations by electric wire or other telegra phic communication.

A train being in readiness atthe terminal station 13 B, its head is brought up so as to be just within the mouth or extremity of the tunnel. The valve-doors K are opened, and the \tllVQS H and L arefshut. A signal is then given to the station 0, when the valvedoors K K are closed, the valve H opened, and the valve L shut. The engine and pump are then started, and by their action the air in the tunnel is quickly rarefied, and motion communicated to the train by the superior pressure of the air behind it. As soon as the train has moved oft into the tunnel, and has reached the point Z, the valve-doors K'are closed after it, and the valve L opened, so as to admit afree supply of air behind the train and avoid a rush of air through the statioi' B B. The train then soon acquires a higt velocity, the air in front being drawn througl' the'shat't and air-passage G G at the statioi CC, and that required to follow behind neing supplied down the air-passageatthe station B B through the valve L, and this velocity is continued until the trainhas reached the point Z at the. opening of the-air-passage G at the station 0 0. After passing this point the power of the pumping'engine acting, thou ghina less degree, behind, instead of, as before, in front of, the train, has a tendencyto draw it in the direction of the station '13 B, and practically assists in bringing the train to rest. Almost immediately after the train has passed the point Z the valve H is shut; but. the train, being carried onward by the momentum it has acquired, and compress: ing the air in the remaining portion of the tunnel, forces open the valve-doors K, and enters the station 0 0, where, by the brakes, it is brought to rest, its head bufling against the air in-the space in the next section of tunnel, as shown on the plan at M. The train remains in this position at the intermediate station so long as may be required, and is then ready to proceed to the next station in advance, in the same manner as has been already described, and so on from station to station It will be seen that while the engine and pump at the intermediate station,'G G, are drawing an up train from the station B B they may at the same time be employed by means of the corresponding valves and air-passages in connection with the next. lengthof tunnel, as

shown in Figs; 4 and 5, in drawing adowu train from the station beyond, which will enter the station G U at the same time, and will occupy the down platform or two complete tunnels,

with air-passages, &c., may be placed side by side,and one of these may be used for up traffic and the other for down trattic..

It is an essential condition for economical working of town railways that the sections into which the-railway is divided should all be of nearly equal length, and I recommend a'length'ot' six hundred ,and sixty yards, or thereabout, as a very convenient length for the section. Provision. should be made for the transfer fot' the trains from the up to the down line and from the down to the up line at then terminal stations, and this latter requirement I accomplish by means oftraversingtablcs or by switchapparatus.

It is to be observed that-in the. working of a line, of \Yl'-ltlt0V6I number of stations, the proportion of trains to stations may be regulated from time to time in accordance with the pumps being connected for the purpose with suitable chambers, and the air passages and valves arranged accordingly.

I now proceed to describe the construction and mode of working when the invention is to be applied to the conveyance of parcels or small packages.

I construct a tube or small tunnel either of brick-work, as shown in Fi 6, of iron and wood, as shown in Figs. 7 and 8, or of other suitable material.

The rails or grooves guiding and directing the motion of the carriage may or may not be bringing them to rest:

Instead of connecting the exhaust-chamber with a single air passages proceedgng from or leading into the tube, I use scvera smaller or branch air passages leading from thc'exhaust chamber, and entering the tube A A at differentpoints, B B B, &c., as shown in Fig. l0,the area of which branches collectively should be about equal to that of the tube. The eifect of this. arrangement will be that while the carriage in their main course will be drawn toward the station with the full force of the pump and full capacity of all the branches up to the point B, beyond that point the propelling power, and consequently the speed of the carriages, will'be gradually reduced. For example, if there be tive such branches, as shown in-Fig. 10, then on passing the point B the carriages will be acted upon only with the power due to the capacity of the remaining four branches. 0n passing the point'B they will be acted upoti only with the velocity "ie to the capacity of the remaining three branches, and so on in succession. Under this arrangement the retarding force due to the rarefication of the air behind the carriages, as well as in front, so soon as they have passed the point B may be allowed to act, and to assist in bringing the carriages to rest, but I prefer that this should not so act, and to avoid it, I place a selt actin g valve upon each branch at the point where it enters the tube, as shown in Fig. ll, so contrived that the valveD will open by the action of the piston E' (shown in that figure) upon the power being turned on in the conveying-tube through the valve 0, (shown in Fig, 10,) and will close again, immediately after'the passage of the carriages, by

the action of the balance-weight F. The valve 0 in Fig. 10 should be closed as soon :as the self-acting valves 1) D, 820., upon the several branches are opened.

The valve G (shown in Fig-10) corresponds to the valve-doors K K, (shown in Figs. 4 and 5,) and may be arranged so as to be kept shut during the approach of the carriage, until it arrives at the point B in Fig. 10, or thereabout, and to be then opened by any automatic contrivance. The velocities will then be regulated solely by the capacities of the several branches, (as influenced by the pumps,) and by the momentum of the carriage, and the carriage must of necessity be drawn home.

'It should be observed that the capacity of each branch air-passage may be determined either by the size of the pipe itself, or by the greater or less opening of the valve within it.

I do not confine myself to the particular arrangements and contrivauces above ,described; but

WhatI claim, as the invention to be secured by Letters Patent, is-- 1. A pneumatic railway or'tube in which the carriages are placed inside the tunnel or.

tube, but are independent of the tunnel or tube, and are wholly supported, and in their motion are guided and directed, by two or more rails, grooves, or trams, and in which the pneumatic pressure is applied over the whole or transverse area of the carriage.

2. The contrivance for filling up with soft material the space between the interior of the tunnel or tube and the outside of the car- 'riage as applied to pneumatic railways and tubes, as above described.

3. The use of several smaller or branch airpassages leading into the tube at different points, either with or without self-acting valves, so as gradually to reduce the velocity of the carriages, as applied to pneumatic railways and tubes, as above described.

T. w. RAMMEL'L.

Witnesses:

R. DUDLEY BAXTER, DAVID BLELLocH, Both of 6 Victoria iStreet, Westminster. 

